Thulium-doped crystals have been used in solid-state lasers, such as Tm:YAG lasers, to generate light at wavelengths of about 1.85 μm to about 2.1 μm for applications including remote sensing (e.g., lidar), dermatology treatments, optical pumping, and other high-power applications. Stimulated emission from thulium at a wavelength of about 820 nm has also been reported in thulium-doped flurozirconate (ZBLAN) glass fibers. Fluorozirconate glass fiber has attractive properties for operation at 820 nm, including long upper-state lifetimes and a guided wave geometry for both the pump light and laser light. On the other hand, fluorozirconate is difficult to handle and fabricate. As a glass, fluorozirconate has low thermal conductivity compared with typical crystals used as laser hosts, and therefore does not scale to high power laser operation.